German Foreign Minister Frank-Walter Steinmeier has arrived on his first visit to Tehran to urge Iran to quickly meet its obligations under the July nuclear deal and discuss the conflict in Syria.

Iran's 10-year agreement with world powers, which takes effect on October 18, allows Iran to maintain a civilian nuclear program but requires the country to show that it is not seeking a weapon and allow UN inspections of sensitive sites, among other obligations.

"Now it's Iran's turn to meet the requirements that were agreed in exchange for an agreement to lift sanctions," Steinmeier said on October 17.

Steinmeier is also pushing for Iran to help find a political solution to the long-running Syrian conflict.

Iran and Russia are the most important allies of Syrian President Bashar al-Assad.